There are numerous reasons that you may want to have raised beds and there are also various ways that they can be built. There are some great pre-built kits out there, but we are going to look at how to build raised bed vegetable garden ourselves.
There are all sorts of materials that you can use for your raised bed, including timber, wicker, brick and more. Here at the Garden Doctor, we like to build our raised bed vegetable garden from timber and that is what we will show you in this article although if you are using another material, that will be fine, you can still read on and see how to do that too!
Why Build a Raised Vegetable Garden
Raised beds are a great way to manage your vegetable growing. Not only are they beneficial for people with mobility problems, but it is also not a myth that having a raised bed vegetable garden will keep your plants healthy and extend the growing season by keeping the soil warmer for longer.
We also like the fact that one of the main benefits of raised garden beds is that you have more control over the quality of your soil. Many gardens do not have ideal soil for growing vegetables as many gardens have soil that is too sandy or full of clay.
Clay does not drain well which can cause roots to suffocate and rot, and sand is not great for your vegetables because it does not hold any nutrients which can cause your plants to starve.
Another positive of having quality soil is that it will help you control the little nasties that may affect your plants.
What to think about before Building a raised bed Vegetable Garden
Although building a raised bed is pretty straightforward, before you think about how to build a raised bed vegetable garden, there are a few things that you will need to consider. You will need to consider the space that you have available in the sun, your height requirements, and your budget.
The beauty of making your own raised bed is that you can build it to your own specifications to make it fit wherever you need it to. You will need to consider the width of your bed as you will want to reach all areas without having to stand on the soil and that includes thinking about how you are able to access the bed for watering and pruning etc.
If you are limited on space you can build your raised bed to any size that you want, you can make small squares or L shapes to fit in a corner or you could build a long and thin bed that will look great as the border to your garden.
If you are not limited on space or have your own allotment, you will have nothing to worry about and if this is the case, we recommend making 3 raised beds which gives you the opportunity to rotate your crops.
Before building, you should think about how high that you want to build your raised bed. Do you want to keep your plants out of reach of children or nosy pets? Do you have mobility issues that may prevent you from bending down for any period? Or do you simply prefer the aesthetic of a certain height over another?
There is no maximum height for a raised bed if you can reach all the plants that you are tending but there is a minimum height, and this is due to the depth of your soil. You will not want to have a raised bed for your vegetables that are less than 18-inches (especially if growing Potatoes).
Building your own raised bed vegetable garden is relatively inexpensive but it is not only the cost of the building materials that you must think of; you will have to think about the cost of the topsoil, compost, and whatever else you choose to fill it with.
What You Need to Build a Raised Bed Vegetable Garden
For the purposes of this article, we are going to show you how to build a raised bed vegetable garden that is (L)8’ x (W)4’ x (D)18” and we will use a technique that can be easily scaled for any dimensions that suit you.
You will need:
- 6 lengths of untreated timber (L)8’ x(W) 6” x(D) 2”
- 6 lengths of untreated timber (L)4’ x(W) 6” x(D) 2”
- 4 untreated timber posts (L)18” x (W)4” x (D)4”
- 48 x 3” Deck Screws
How to Build Raised Bed Vegetable Garden
Step 1. Consider Position and Height
As we mentioned earlier, by now you will have decided on where you want your raised bed to go and its height. Hopefully, you will have levelled the ground as having level ground not only makes building the raised bed easier, but it will also help make it last longer as there will be less stress on the wood and joints.
Step 2. Build the Base Frame
- You will build the frame by attaching 2 of your timber posts to the end of one of the 4’ lengths of timber making a U shape.
- Repeat with the other 2 posts and another 4’ length. Now you will have 2 U shapes.
- With the posts inward, you will want to attach the 2 ends with the longer 8’ boards making a rectangle.
Step 3. Finish the Frame
Now you have the base of the frame you can stack the other boards appropriately.
Step 4. Fill your Raised Bed Vegetable Garden with Soil
Now you have the frame for your raised bed vegetable garden completed, you will need to fill your new frame with soil. What you choose to fill your raised bed with is especially important for your vegetables.
Best Soil Mix Raised Bed Vegetable Garden
There are a whole load of different mixes and compositions that different gardeners will swear by and all can be successful with the right amount of feeding and cultivation but we believe that the best soil mix for a raised bed vegetable garden is 60% screened topsoil, 30% compost and 10% potting soil.
60% Screened Topsoil
Screened topsoil is available for delivery from most builder’s merchants and will come in handy tonne bags which will save you and your car bringing loads back from the garden centre. Good quality topsoil will be free of any lumps or large stones making it easier for tilling and planting your new crops.
Compost or well-rotted manure will be available at many farms and it is quite inexpensive. At the Garden Doctor, we like to make our own compost but do not worry if you cannot do that, farm bought compost and manure is fine. This is our organic matter that will provide our vegetables with plenty of nutrients.
10% Potting Soil
Potting soil is not actually soil at all. Potting soil or potting mix as it is known is a mixture of peat moss, perlite and/or vermiculite.
Potting soil is a porous material that will aid in the drainage of your soil.
How to fill Raised Bed Vegetable Garden
Once you have decided on the right soil mix for your vegetable garden, you will have to think about adding it to the garden. Our gardens are placed on an area that drains well so we do not have to worry about adding any sticks or shingle to the bottom of the bed. We fill our bed in the autumn so that we are able to put as many fallen leaves as we can into the lower levels of our soil.
You can add the ingredients to your mix however you wish but we like to line the bottom with a thin layer of compost and then we will give the rest a good tilling so it is all mixed nicely.
There you have it; this is how to build a raised bed vegetable garden. It may seem like a lot of hard work but in reality, it is far easier to build and manage than just digging up the garden. Hopefully, you will have read this and be confident enough to give it a go yourself or even get the kids involved and help them learn and see the whole process from starting the bed, all the way to eating the veg!
There are also many other ways to build your vegetable garden as we mentioned earlier. If you are building one in the garden, you may want to build it with bricks as they will be more aesthetically pleasing, or you may like to recycle and want to build one with some old, corrugated iron. The choices are endless.
If building one seems like it is too much hard work, you could always buy one here! (amazon link – opens in a new tab).
Garden Doctor Tips
“Make sure to use untreated or old timber if you are building the raised bed for vegetables. Treated timber is OK if using for flowers or ornamental plants!”
“Build your raised bed vegetable garden in the Autumn so you can add fallen leaves to the lower levels of the soil!”
“Keep a healthy compost bin throughout the year and fill it with organic matter to add to your raised bed!”
“If your raised bed vegetable garden is on concrete or a base that has little or no drainage, put a layer of shingle in the bottom!”
Frequently Asked Questions
What do you put in the bottom of a raised garden bed?
If the location of your raised bed has very little or no drainage, it is good practice to have a good 2-inch layer of stones or shingle in the bottom to allow any excess water to drain from the soil. Soil that is too wet can damage the roots of your Vegetables and make them rot. Climate is also important as in warmer climates you may want to add a liner to the bottom to hold water.If the location of your raised garden bed has good drainage, and is on a level surface, I wouldn’t add anything to the bottom so that worms can come and go as they please.
Best size for raised garden bed?
There is no best size that will apply to everyone. A lot of people will have different requirements and will build their bed to suit them. You will need to consider your accessibility for tending, pruning and watering.
Our preferred size for a raised garden bed is 8′ x 4′ x 18″ and to ensure good crop rotation, we have 3 of these together.
How much space for a raised vegetable garden?
As much space as you have available.
If you are just beginning, you can start small and as you become more confident, you can scale it up to whatever suits you!
How deep should my raised garden bed be?
For most flowers and ornamental plants, 6-12 inches will be adequate although most vegetables will require approximately 12-18-inches of soil.
For our vegetables, we never go below 18-inches.
Where can I build a raised bed?
You can build your raised bed anywhere although you will have to consider the warmth and light that the bed receives.
You will also need to consider your access to the bed so that you can look after your plants.
What is the best mulch for vegetable gardens?
Leaves & Grass Clippings. The best mulch for vegetable gardens is a mixture of chopped leaves and grass clippings.
Chopped leaves and grass clippings is a great organic mulch that will not take too long to decompose and add nutrients to your soil.
They also make a great insulator, keeping the soil warm and also keeping those pesky weeds at bay.
How do you mulch a raised garden bed?
Add approx 2-inches of mulch material to the top of your soil keeping a 2-inch space around the stems of your plants to reduce the risk of fungal infections and disease contamination.
We prefer to use organic matter like chopped leaves and grass clippings but there are other things like plastic sheeting and straw that are also widely used.